US Patent 7920891 Stand alone emergency signal device housed in cell phone

The emergency signal device includes an emergency key on the phone, an independent IC chip set controlling the emergency functions, a dedicated memory chip for emergency information and a by-passing outlet to the cell phone's transmitting parts. It is further provided that the device includes a global positioning system (GPS) receiver, so that the person in danger may always be located. This device utilizes rechargeable solar cells to provide energy. All of its components are powered by a solar cell or solar cell charged battery.